All case studies

Company

iRock Technology Co., Ltd. is a rock-core analysis company with headquarters in Beijing, China. iRock offers integrated services and software to the oil and natural gas industry to provide a better understanding of their reservoirs and to improve recovery in conventional and unconventional reservoirs. A key technology to provide these services is called digital rock analysis.

The challenge

Digital rock analysis is a pore-scale imaging and numerical modelling technology to extract nanometre to centimetre scale geological and petrophysical information, as well as multi-phase fluid-flow data based on pore-scale displacement processes from digitized rock samples. One of the benefits of this technology is the capability to provide a large number of rock properties within a very short time compared to traditional physical laboratory experiments.

A prerequisite for calculating representative rock properties are high-quality 3D multi-scale images of a rock sample that capture the representative elementary volume (centimetre-millimetre) and at the same time resolve the finest structures, such as the smallest pores (micrometre-nanometre scale). Computed tomography is currently the best-suited technique to acquire 3D images of rock samples over several decades of length scales.

Due to the fulminant development of benchtop CT and micro-CT hardware during the past decade, it is nowadays possible to image decimetre to millimetre-sized rock samples at voxel sizes of few hundred microns down to one micron at good quality and within an acceptable time of minutes to several hours per sample. However, CT imaging with benchtop micro-CT machines below 1-micron voxel size are of lower quality and are extremely time consuming (>1 day/sample); imaging below 0.5 microns/voxel is not possible at all, in a reasonable time and with acceptable quality.

The crux is that approximately more than 60% of the reservoirs worldwide consist of rocks with very small pore systems, which require imaging at voxel sizes (far) below 1 micrometre with ideal scanning resolutions between 100 and 300 nanometres/voxel.

A partial solution is to use a dedicated nano-CT device for imaging but these machines are delicate with respect to stability, maintenance, flexibility in sample and voxel size and scanning times. So is the maximum sample diameter around 60-70micrometres and the voxel size is fixed to 65 nanometres.

Even if this machine is used in conjunction with micro-CT we are left with a gap in scanning resolution between 65 nanometres and approx. 1 micrometre per voxel. This is unfortunately exactly the voxel-size range required for the majority of reservoirs rocks.

Solution

With their flexibility in energy ranges, spot sizes and detection architecture, beamlines at ESRF can CT-scan our rock samples with varying sample diameters at resolutions ranging from micro- to nano-scale. Due to this capability it is possible to close the resolution gap, which is essential to investigate many reservoir rocks.

A regular micro-CT, imaged at 1 micrometre voxel size, shows that a large proportion of the pore space in the rock is unresolved. On ID19, by imaging at 280 nanometres per voxel the results do not show partial volume effects and resolve the entire pore space (Fig. 2).

The effects of unresolved voxels in digital rock analysis are dramatic, since a clear segmentation of the rock phases is not possible. Every voxel layer that is classified into a wrong rock phase can offset subsequent calculations by orders of magnitude and leads to inadequate simulation results.

Access to the ESRF beamlines offers quick and high-quality imaging at flexible voxel sizes and a range of sample sizes, which is not achievable with laboratory CT machines. The acquired images provide a profound base to build representative 3D digital rock models and extract rock properties at a high confidence level.

Benefits

Next to the image quality, the higher sample throughput compared to laboratory devices helps iRock to plan and conduct projects for the oil and gas industry in shorter time. The oil and gas companies, in turn, benefit from great time savings in comparison to their traditional methods - weeks and months instead of several years for a typical project.

Company

CRELUX GmbH (a WuXi AppTec Company)

Challenge

AMPK (AMP-activated protein kinase) is a Ser/Thr kinase composed of two regulatory subunits and a catalytic subunit that together as a complex regulates the levels of energy in the cells. This complex is evolutionarily conserved and ubiquitously expressed. There are a total of 12 possible isoforms, which are distributed in the human body in a tissue-specific manner. For example, one isoform is highly expressed in skeletal muscles and a different isoform is more specific to heart, brain or liver. All in all, AMPK senses the energy levels of the cells (in the form of the so-called ATP) and allows upstream signals to activate it, in response to external nutritional stress. AMPK substrates are involved in lipid metabolism, autophagy, mitochondrial biogenesis, and in the maintenance of glucose homeostasis. Therefore, this complex is a highly promising therapeutic drug target against diabetes, obesity, Wolff-Parkinson-White Syndrome, cancer, and aging.

There are, however, several challenges to generate soluble and stable complexes, and this is one of the many reasons why not many X-ray structures are available, especially at resolutions suitable to drive drug discovery efforts. Firstly, it is very complicated to be able to make crystals of the complex with the activated compound bound to it. Another obstacle is the extreme sensitivity of the tiny crystals to radiation damage.

CRELUX/ WuXi AppTec, a company expert worldwide in premium drug discovery solutions for global pharma, biotech and research organizations, came to the ESRF to tackle this challenge.

Sample

CRELUX/WuXi AppTec used their expertise to design and produce a fully functional AMPK complex with the needed yield, purity, and specific post-translational modifications for successful crystallization and X-ray structure determination of an active complex. The AMPK sample contains an kinase activating compound and three AMP nucleotides (ATP-depleted scenario) bound to it.

Solution

CRELUX/WuXi AppTec scientists sent crystallized AMPK samples to the ESRF’s ID30-A beamline. Because of the complexity of the project, they needed a powerful beamline, state-of- the-art detector and a skillful scientist in-house to carry out the experiment. They managed to solve the structure of the complex at a resolution of 2.9 Angstroms, which was enough for CRELUX/WuXi AppTec to see the detailed chemical enviroment of the compound in the complex binding site. This corresponds to one of the highest resolution structure published so far for any AMPK isoform.

Benefits

The work at the ESRF will help CRELUX/WuXi AppTec to support their clients in the discovery and development of novel and more specific drugs that can influence AMPK activity in the cell and, as a result, adjust the energy balance in disease affected organs. Debora Konz Makino, Lab Head at CRELUX/WuXi AppTec, explains: ”Our long-standing collaboration with ESRF has greatly contributed to the success of most of our client's projects in the early stages of drug discovery. ESRF provides not only cutting edge infrastructure, but also excellent scientific support for X-ray data collection of biological macromolecules. We at CRELUX highly appreciate ESRF prompt and open communication.”

Chronic pain is an important and unmet medical need that affects the quality of life for millions of people worldwide. Available treatment options include opioids and non-steroidal anti-inflammatory drugs that can be effective but often have unwanted side effects, limiting their therapeutic utility.

Genetic studies in humans have recently identified a mutation in the voltage-gated sodium (Nav) channel, Nav1.7, which causes people to lose the ability to feel pain. Intense efforts have been underway to identify antagonists that selectively inhibit only the Nav1.7 channel but leave the other eight human Nav channel isoforms unaffected. It has been a major challenge to identify selective Nav1.7 channel inhibitors because all nine Nav channel isoforms are highly related in sequence, and all clinically available Nav channel blockers are poorly selective.

Sample

Nav1.7 contains four peripheral voltage-sensor domains (VSDs) that surround and control a central ion pore domain that allows sodium ions to enter and initiate action potentials in sensory neurons. Researchers from Genentech, in collaboration with Xenon Pharmaceuticals, wanted to study a new class of inhibitors that appear to target the fourth voltage-sensor domain (VSD4) and selectively inhibit the Nav1.7 channel. Because high-resolution structural studies of the human Nav1.7 channel are hindered by the molecules complexity, these researchers exploited a simpler bacterial Nav channel by fusing portions of human Nav1.7 (i.e. VSD4) onto it.

Solution

The Nav1.7 VSD4-bacterial channel fusion protein was crystallized and high-resolution diffraction studies were conducted at beamline ID29. The resulting crystal structures revealed the details of how the new class of inhibitor directly interacts with residues within the fourth voltage-sensor domain to selectively and potently inhibit the Nav1.7 channel.

Benefits

The new structures provide insight into the mechanism of voltage sensing and can enable the design of more selective Nav channel antagonists. Hopefully these results may accelerate the development of treatments for pain that selectively target Nav1.7 and aid drug design efforts aimed at other voltage-gated ion channels.

Envelope of the molecule calculated from the SAXS-data (top); conformation of the antibody as determined by X-ray crystallography (middle); Y-shaped conformation of a different antibody that fits to the SAXS-data (bottom).

Company

Boehringer

Challenge

Antibodies are a vital part of our immune system. These proteins bind to specific antigen proteins on the surface of foreign bodies such as bacteria and viruses in order to neutralize or disarm them. Since each antigen has a different shape, it requires a different antibody to attach to it. By tailoring antibodies to attach to proteins responsible for specific diseases, pharmaceutical companies seek to develop drugs that minimise side-effects caused by antibodies binding to the wrong targets. Researchers at Boehringer have been studying a molecule in an antibody and they found that it was unusually compact as a single crystal. The next step was to obtain structural information of the molecule in solution.

Sample

The antibody molecule in solution.

Solution

Using Small Angle X-ray scattering, the team managed to compare the measured scattering curve with that calculated from the X-ray structure they had previously solved. The results confirmed that the compact conformation does not exist in solution. Instead, the molecule adopts a Y-shaped conformation, commonly known for antibodies.

Benefits

SAXS experiments can help pharmaceutical companies to double-check the results they get using their own characterization techniques. SAXS is also complementary of X-ray macromolecular crystallography, and, as proven here, can confirm or deny previous results.

Company

Jaguar Land Rover and University of Warwick

Challenge

Energy absorption is important for the safety of car passengers. Besides the seat foam used for comfort, modern vehicles have a denser foam such as expanded polypropylene (EPP) inside headrests and bumpers that decelerates passengers in such a way as to minimise any stresses on them. Ideally, a foam would do this by deforming in a controlled manner, reducing the maximum forces experienced by the occupant.

Solution

The researchers studied EPP’s energy-absorption properties under deformation at the ESRF, using new material models to improve a computer-aided design process. At the beamline ID19, the researchers performed microtomography, which enabled them to continually image their EPP foams (see figure above) as they were slowly compressed with a dedicated press facility. Incorporating the images into a three-dimensional computer model, the researchers could analyse them to understand how to improve the foam, and how much of it to use in a vehicle for optimal performance.

Benefit

The benefit of the ESRF in this research was the ability to track the deformation in situ an in great detail. “The facilities available at the ESRF will allow us to improve the use of polymer foams as energy absorbers in our vehicle range”, expalins Mark Blagdon, a materials engineer who led the project from Jaguar Land Rover.

Company

University of Hamburg, University of Siegen, DESY, MAXIV

Challenge

Catalysts in a car contain noble metal nanoparticles consisting of rhodium, platinum and palladium and alloys thereof. These make the harmful molecules produced by the motor react on the surface of the converter while reaching high temperatures and reducing and oxidising atmospheres. When catalysts operate, the particle size of the noble metals increases. It is a process called sintering, which results in a decrease of the overall catalyst surface area. In the long run, this reduces the number of active sites from the surface and makes the catalyst less efficient.

Sample

The sample consisted of stripes of platinum-rhodium nanoparticles with varying composition from pure platinum to pure rhodium and a constant height.

Solution

Synchrotron radiation makes it possible to carry out operando experiments where scientists can monitor nanomaterials while the catalytic reaction takes place under realistic thermal and process conditions. The team used high-energy grazing incidence X-ray diffraction and online mass spectrometry.

Benefits

The experiments focused on the behaviour of the alloy nanoparticles during catalytic oxidation of carbon monoxide to carbon dioxide at a temperature of 550 K and near-atmospheric pressures. The results showed that platinum particles increase in height and lead to a reduction of the total particle surface coverage. This did not happen so much with the rhodium and rhodium-rich particles, which indicates that rhodium might be an important ingredient for catalyst stabilization.

Company

Vienna University of Technology (TU WIEN), German Aerospace Center (DLR)

Challenge

The transportation sector moves towards greater energy efficiency in all areas (i.e. from component production over to fuel consumption) in order to meet the latest performance and environmental targets. The success and progress fulfilling these goals is highly dependent on the availability of new engineering materials and manufacturing methods that enable significant weight savings associated with simultaneous improvements in component performance. Titanium alloys exhibit higher specific strength than other structural materials as well as excellent corrosion and creep resistance up to about 500 °C. These properties represent many performance advantages for the transportation industry. Despite these benefits and the relatively large resource reserves (titanium is the fourth most abundant metal in the earth’s crust), titanium alloys still come at high production costs that limit their industrial usage.

Titanium-based components are mainly produced via the classical process of ingot metallurgy (cast and wrought) which provides alloys with high strength levels. At this stage of manufacturing, thermal and thermo-mechanical treatments determine the microstructural characteristics, i.e. the mechanical properties of titanium alloys. On the other hand, selective laser melting (SLM) is a very promising powder-bed based “3D printing” technique that manufactures near net-shape metallic components with higher resource-efficiency than conventional fabrication methods. Consequently, considerable cost savings can be achieved. One of the main key strengths of SLM is that extremely complex geometries inaccessible using conventional manufacturing techniques can be manufactured. In this way, structures of minimal weight and optimized functional performance can be produced. However, the very fast cooling rates reached during solidification of molten metal pools during SLM produce brittle titanium based components with poor mechanical performance.

Monitoring the kinetical evolution of the microstructural phases of titanium based components during thermal and thermomechanical treatments would help scientists rationalize their processing either via ingot metallurgy or advanced SLM while improving their mechanical performance (e.g. strength and fatigue resistance).

Sample

The a+b Ti-6Al-4V and Ti-6Al-6V-2Sn as well as the metastable b Ti-10Al-2Fe-3Al, Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-5Al-5Mo-5V-3Cr-1Zr titanium alloys presenting different initial microstructures.

Solution

The researchers carried out in situ high energy synchrotron X-ray diffraction experiments at the ID15B beamline. Image sequences of complete Debye–Scherrer rings from the bulk of the studied alloys were recorded in transmission mode while heating and cooling the sample within the same temperature ranges used in the industry. This allowed univocal determination of the phase transformations kinetics (i.e. the evolution of the volume fractions and lattice parameters of phases) which confine the microstructural changes of the alloys, i.e. their mechanical properties. Moreover, three-dimensional (3-D) imaging was performed at the ID22NI beamline by high-energy magnified synchrotron tomography using Kirkpatrick–Baez focusing optics, to analyse morphological features of the microstructure (e.g. non-uniform distribution of phases, formation of complex structures, or contiguity between them) and understand their relationship with the mechanical properties of the studied alloys.

Benefits

The studies provide an advance in the current knowledge of the phase transformation kinetics of titanium alloys mostly discussed in the basis of stable conditions (e.g. isothermal aging and ex-situ experiments). This will help to develop new theoretical models for microstructure prediction leading to improvements in functional alloy design, lead-time and cost savings via knowledge-based thermal treatment optimization. Particularly, the results obtained will contribute to overcome the present manufacturing restrictions of SLM manufacturing.

Company

Unilever

Challenge

Hair conditioners are based on a dispersion of liquid crystalline phases that work with the flow of water to lubricate and protect hair fibres. The stability of such products is vital for guaranteeing consistent performance. The validation of stability can be done with characterisation techniques that measure physical properties of the bulk product, such as rheology, pH, light scattering and calorimetry. However, it is difficult to understand what and how underlying microstructures influence the bulk properties and any changes that occur over time.

Sample

Ingredients of conditioner products and their permutations.

Solution

The team used small angle X-ray scattering at ID02 to monitor the microstructure evolution of the products at critical intervals during a three-month trial.

Benefits

The experiment proved instrumental in providing a mechanistic understanding of how a hair conditioner microstructure evolves with the passage of time, from factory to consumer.

Company

Procter & Gamble (P&G)

Challenge

As much as 90% of the energy used to wash clothes goes towards heating the water in washing machines, so one of the main goals for companies like P&G is to develop detergents that work at lower temperatures. The majority of liquid detergent formulations exist as micellar solutions to ensure easy dosing and fast dissolution, but this requires the formula to have a high water content. If the water content is reduced, liquid crystals will start to form unless organic solvent is added, which adds more to the cost of a product and dents its environmental credentials. Another approach is to formulate it as liquid crystal, but the presence of other ions typically destabilises the product and causes “phase splits”.

Sample

Anionic surfactants, enzymes, polymers.

Solution

Researchers at P&G want to have a better knowledge of the microstructure of the colloidal formulations in order to tune the performance and stability of products, and meet the company´s environmental sustainability targets. Small Angle X-ray Scattering was used to map the phase diagram of Ariel Excel Gel to determine the regions that are physically stable within the formulation space of interest.

Benefits

Ariel Excel Gel, boasts cleaning at 15 °C thanks to specially designed enzymes and polymers, offering considerable energy savings. It is also highly concentrated, requiring less water to manufacture and reducing transport and storage costs. It has become the first liquid detergent with a liquid-crystal microstructure with the lowest water content possible without the use of organic solvent.

Fuses can be found in most electrical circuits, where they protect electrical components against current surges. Despite their widespread use, however, nobody has ever watched what happens to a fuse as it explodes. With fuse breakdown typically taking place on timescales much less than a millisecond inside an opaque medium, in situ observations were thought impossible. Generating power from wind turbines and other intermittent sources relies on DC converters and fuses, but these tend to be bulky and complex compared to familiar AC versions. In DC circuits, the fuse has to manage current-interruption without profiting from the voltage passing through zero. Also, there is a big interest in reducing the dimension of the fuse because long fuses increase the inductance of the circuit, which is detrimental to DC inverters.

Solution

The SIMaP team used X-ray 3D microtomography on ID19 on commercial and test fuses to understand the interaction between electrical arcs and matter. The beamline allowed the team to measure the speed and lifetime of “burn-back” – an important process whereby the electrical arc damages the electrode material and creates silica cavities in the arc channel. Although previous post-mortem studies had shown various phenomena, they revealed little about the temporal characteristics of the process.

Benefit

Tracking the ultrafast processes that take place in fuses during electrical breakdown helped Mersen develop advanced compact fuses for renewable energy applications.

Breakdown of an electrical fuse at time intervals of 25, 100 and 500 picoseconds (left to right) following a current spike, showing the effects of sand (right half of each panel) in the arc-quenching channel.

Company

SILTRONIC (Germany)

Challenge

Silicon, the workhorse of the semiconductor industry is coming up against its physical limitations. To continue driving the increased speed, miniaturization and functionality of microelectronics, manufacturers are pairing silicon with other materials in order to enhance its properties. However, any imperfection in the microscopic structure of materials can severely affect the performance of the semiconductor devices. This is even more critical when matching two different materials.

Solution

ID01’s scanning X-ray diffraction microscopy technique allows industrial researchers to detect the slightest imperfections in heterogeneous structures and thin films, even when stuck in different layers.

Benefits

The ESRF x-rays allowed SILTRONIC to establish a partial correlation between real-space morphology and structural properties of the sample at the micrometre scale. Results showed strain field fluctuations occurred due to the underlying dislocation network and that they diffused to the surface during growth.

Company

Challenge

Photovoltaic (PV) cells are mainly made of silicon, but organic polymer based PV cells offer a cheap and mass producible alternative with a low environmental impact. The efficiency of organic PV cells is poor and decreases markedly over time. So far they are not being used routinely in industry because they need to be able to harvest light more efficiently. Metallic nanoparticles added to the polymer layer allow localised surface plasmon resonances absorb light and promise high performance and durable solar cells.

Sample

Organic PV cells, made of a conjugated polymer and a soluble fullerene derivative.

Company

TU Delft together with steel manufacturers

Challenge

The Twin Towers collapsed in 2001 because the steel that kept them standing couldn´t resist the fire. The changes in temperature modified the microstructure of the steel and it lost its strength, making the towers crumble. Knowing what happens inside steel (the nucleation process) when it is submitted to high temperatures could help find a better composition for this alloy.

Sample

Steel.

Solution

3D X-ray diffraction on ID11 has proven a unique technique to track the nucleation process inside steel as it is submitted to temperatures of 1000 C. Scientists came up with a furnace that could be compatible with the beamline and that had temperature control. They found that nucleation, which is a key process in metals, happens quicker than literature had predicted: there are special places, like grain corners or edges in the material where nucleation takes place more easily than other areas. Amongst these corners and edges there are ones that are preferred for nucleation. Controlling the nucleation means controlling the properties of the material.

Also, the crystals in the steel become coarser at higher temperatures, which decreases the material's strength. Scientists are currently testing the replacement of potentially scarce elements in the alloying process of steel by other elements more widely available.

Benefits

A better “recipe” for steel using less alloying elements would make the material more fire-resistant, less expensive and easier to recycle whilst maintaining its properties.

Company

University of Mancherster and Rolls-Royce

Challenge

Crack propagation in metallic materials is well understood. But aircraft manufacturers are increasingly turning to more complicated composite materials that are lighter, stronger and can operate at higher temperatures. Lower weight reduces fuel consumption, while higher engine operating temperatures allow aeroengines to be more efficient. The challenge is to understand how cracks propagate in such materials.

Sample

Titanium reinforced with silicon carbide fibres. This composite material can operate at higher temperatures than titanium alone, making it a promising candidate for jet engine parts.

Solution

Synchrotron X-rays penetrate tens of millimetres into a sample where the behaviour of cracks can be very different - this in contrast to eectron microscopy which only reveals the surface features of micro-cracks. On beamline ID15, scientists can use imaging, to see how cracks grow, and diffraction, which tells them about the local stresses that the cracks grow under.

Benefits

The ability to monitor cracks under load at high temperatures allows researchers to evaluate the potential of these materials under realistic conditions. It also helps to make realistic estimates

of the lifetime of existing components and to design safer, more crack-resistant materials for the future.

Better knowledge of crack propagation transfers directly to other industries in which failure is unacceptable, notably the nuclear industry.

Company

CNRS, MIT and the University of Haute-Alsace

Challenge

Limited petrol reserves are pushing oil companies to try to find new access to oil and gas. Drilling companies claim that trillions of cubic feet of shale gas may be recoverable, just in the UK. Accessing the rock is complicated. Kerogen is the organic matter which hosts hydrocarbons in gas shale structures. It is compressed within rocks a million times less permeable than in conventional hydrocarbon reservoirs. Hydraulic fracturing, or fracking, consists of drilling down into the earth and then directing a high-pressure water mixture to the rock that contains gas or oil inside. Researchers still don’t know much about kerogen. More knowledge could open doors to more environmentally-friendly extraction techniques.

Sample

The international group of scientists studied four different kerogen samples of different origin and degree of maturation.

Solution

The X-ray scattering technique on beamlines ID11 andID27 at the ESRF gave them access to the chemical composition of the kerogen, its texture and density. At ID27, the sample was placed in a diamond anvil cell with a pressure of up to 5.1 GPa to reconstruct the conditions underground.

Benefits

Using a hybrid method, combining an arsenal of experiments and molecular simulations, the team developed molecular models of kerogen with different maturities. These atomistic models were then validated by comparing them with experimentally accessible kerogen properties. They unravelled the adsorption, mechanical, and transport properties of this organic matter. The new findings should now help understand the microscopic behaviour of this disordered and heterogeneous matter and open doors to improved extraction technology.

Company

Challenge

Grains are a main component in the human diet and a major source of essential mineral elements. Unfortunately, many of these elements, such as magnesium, zinc or iron, for example, are tightly bound in the so-called phytate salts and the body does not easily absorb them. There are some ways of making these elements more bioavailable, namely through thermal and mechanical processing, soaking, fermentation, and germination/malting of seeds and grain. These processes enable the release of tightly bound mineral elements, especially those bound in phytate.

Among mineral elements, iron is particularly poorly bioavailable, and this is especially problematic in vegetarian diet. Researchers are now working to determine speciation and bioaccessibility of iron in processed grains in comparison to un-processed grains. Knowing only the amounts of iron in foods is not enough, researchers need to determine speciation and binding states of iron to understand the bioavailability of iron. Having great concentrations of iron is not effective if all iron is bound too strongly to be absorbed during digestion. Fortification is a costly procedure and not very efficient in the case of iron, as iron is easily reduced and can affect the taste of the produce. Promoting staple food as a good source of bioavailable iron, especially for gluten intolerant individuals (they can consume buckwheat), would be interesting for industry.

Sample

Tartary buckwheat is a gluten-free crop with great potential as a wheat substitute. It has relatively high concentration of iron, which occurs predominantly bound in phytate. The team studied the mineral element concentrations and iron speciation in grains and their processed counterparts, namely groats (hydrothermally processed grains that have the outer grain layers removed) and sprouts (7-day-old seedlings). Grains and groats of two buckwheat species were obtained from Mlin Rangus (Slovenia).

Solution

The ESRF micro-X-ray fluorescence spectroscopy’s beamline ID21 provided the spatial distribution of mineral elements and iron speciation in grains, groats and sprouts It also showed that germination affects the mineral element distribution and speciation of iron. They found that iron bioaccessibility was 4.5-fold greater for grains than groats, suggesting that iron is more bioaccessible in the outer layers of un-processed grains than in the rest of the grain. Bioaccessibility of iron in sprouts was lower than in the grains indicating that germination does not favourably affect the bioaccessibility of iron.

Benefits

This study showed that iron in the outer layers of the grain is most bioaccessible. It would be thus useful to include part of these layers in the flour and in products produced from tartary buckwheat flour to ensure greater iron intake. Iron dense products are highly desired for alleviation of iron deficiency, which occurs particularly in pregnant and breastfeeding women, children and elderly.